The effects of sucrose on the gelatinization and retrogradation of acorn starch were studied by differential scanning calorimetry, compression and longitudinal oscillation measurements of cylindrically molded gels. All these measurements showed that sucrose retarded the retrogradation of acorn starch effectively. Regelatinization enthalpy of acorn starch dispersion stored for 14 days depended strongly on the concentration of added sucrose but not so much for the dispersion stored for one day, suggesting that the interaction between sucrose and amylose is less important than the interaction between sucrose and amylopectin.